Controlling means



Aug. 14, 1934. v R. c. OSGOOD 1,969,759

CONTROLLING MEANS Filed May 22, 1929 Patented Aug. 14, 1934' Robert 0. Osgood; Clatemont, N. 11., assignor to Sulkivan Machinery (lompmiy; aiacorporation' of Massachusetts 1 I Application May 22.1929 SctieiliNoltGSilGZ V 3 Claims. (6.188482) This invention relates to controlling means for hoisting mechanisms.

More particularly, my invention relates to mechanism for controlling rotation of the winding drum of a hoist.

An object of my invention is to provide an improved mechanism for controlling the rotation of the winding mechanism of a hoist. A further object is to provide improved means for holding 1Q stationary the winding drum of a hoisting mechanism. A still further object of my invention is to provide rotation-preventing mechanism for a hoist which shall be automatically released when it is desired to lower the load. Other objects and advantages of my invention will appear from the following description and willbe further pointed out in the claims.

In the accompanying drawing I have shown for purposes of illustration one form which the invention may assume in practice.

In this drawing,

Fig. 1 is a view in side elevation of a hoisting mechanism in which is incorporatedan illustra-' tive embodiment of my improved control mechanism, the right end of the drum together with the control mechanism being shown in section to facilitate illustration.

Fig. 2 is an end view in elevation taken from the right end of Fig. 1.

Fig. 3 is a detail view in side elevation of a ratchet and pawl mechanism, the normal position of the pawl being shown in dotted lines.

Fig. 4 is a plan View of the pawl.

In the illustrative example shown in the drawing, a hoisting mechanism H comprises a base 5 upon which is supported a driving motor 6 and a mechanism generally indicated by the numeral 7 and comprising driving and controlling mechanism and a drum 8. To drive the drum, in addition to reduction gearing (not shown) en'- closed within a casing 9, there is provided a friction-controlled planetary gearing 10, controlled by an operator-controlled friction band mechanism 11. This'planetary gearing is of the same general type as that disclosed in Patent No. 1,740,707, December 24, 1929, whicheffects rotation of the winding mechanism when the brake mechanism 11 is applied, the reaction member of the planetary gearing rotating idly when the brake mechanism 11 is released.

The drum 8 is provided at its right end with a flange 12 whose outer surface 13 cooperates with a brake mechanism 14, the inner surface of the flange 12 being provided with ratchet teeth 15.,

5 The right end of the drum is formed with a hub portion 16 which is rotatably mounted in a standard 17. The central leg 18 of this standard is recessed on the inner side to receive a stub shaft 19 which is secured in position by a screw 20. I have provided, to cooperate with the teeth 15, 59 means automatically releasable when the drum is turned in winding in direction and thereafter automatically maintained in released position until moved therefrom, but movable into a posi-- tion to engage the teeth and positively prevent drum rotation in unwinding direction. Herein these functions are fulfilled by a pawl 21 rotatably mounted on the stub shaft 19, the weight of the pawl being so distributed that the pawl normally assumes the position shown in dotted lines in Fig. Z11 3. As shown in Fig. 4, the pawl 21 is provided with a nose 22 for engaging the ratchet teeth 15, the opposite end of thepawl being formed as a handle 23.

In the operation of the control mechanism, '15 the planetary gearing 10 is controlled so as to effect rotation of the drum 8 by means of the friction band mechanism 11. When the load has been lifted to the proper height, the operator applies the drum brake l4 and releases the 8,0

friction band mechanism 11, and then, having grasped the handle 23 and brought the nose 22 of the pawl 21 into engagement with a ratchet tooth 15, releases the brake mechanism 11 so that the load is held by the pawl 21 and any danger of dropping by reason of slipping of the brake 14 is eliminated. When it is desired to lower the load, it is merely necessary to operate the friction band mechanism 11 to elevate the load slightly, whereupon the pawl 21 will no automatically rotate on the stub shaft 19 into the inoperative, dotted line position (Fig. 3). The load may then be lowered in the customary manner, as under control of brake 14.

From the foregoing description it will be ap- Q5 parent that I have provided improved controlling means for a hoisting mechanism whereby heavy loads may be certainly, positively and safely supported in raised position, and yet lowered with usual facility under frictional control.

While I have in this application specifically described one form which my invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims. 7

What I claim as new and desire to secure by Letters Patent is: i

ly moves to inoperative position when released from engagement with said teeth.

2. In a hoisting mechanism, a winding drum",

driving means therefor, and means for .holdeing said drum against rotation; comprising.

a bracket, a substantially horizontally extending pawl pivotally supported intermediateits ends,

on said bracket, a combined handle and weight extending laterally from one end of said pawl,

and so positioned as to at all times move at the same angular rate'with said pawl and constantly urging said pawl toward releasing position, and a pawl engaging ratchet associated with said drum whereby upon engagement of the pawl and ratchet, rotation of the winding element is prevented.

-3.'In'a' hoisting machanism, a winding. drum, driving means therefor, and means or holding said drum against rotation comprising a bracket, a substantially horizontally extending Zpawl pivotally supported intermediate its ends on theinside of said bracket, a combined handle' and weight extending laterally from one end of said pawl through an opening in said bracket, and a pawl engaging ratchet associated with said drum whereby upon engagement of the pawl and ratchet rotation of the winding element is prevented.

. ROBERT C. OSGOOD.

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